Automotive Parts, Accessories, and Tire Retailers (U.S.)

NAICS 2022 code 4413 — an investor's primer (industry-group rollup). This page synthesizes the two child primers (44133 auto parts, 44134 tire dealers) plus our own ground-truth federal statistics for this exact four-digit level. Figures are reported facts with sources; statements about the future are labeled as judgments. Ticker symbols, yields, and valuation multiples are reserved for the investable-universe and how-to-invest sections; every acronym is defined on first use.

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1. Overview

NAICS (the North American Industry Classification System, the U.S. government's standard scheme for grouping businesses) code 4413 — Automotive Parts, Accessories, and Tire Retailers is a four-digit industry group: the level that gathers together the specialty stores keeping America's existing cars on the road [1]. It has two moving parts — the counter that sells you a battery or a brake pad, and the bay that mounts and balances your tires — and NAICS puts both under one roof because they serve the same customer (the owner of an out-of-warranty vehicle) for the same reason (wear and repair, not new-car buying).

This is one of the more defensive, cash-generative corners of U.S. retail. Its demand comes from the roughly 289 million light vehicles already on the road — a fleet whose average age hit a record 12.8 years in 2025 — rather than from new-car sales, so it holds up, and can even improve, when the economy softens and people repair instead of replace [6]. It is also fragmented: tens of thousands of firms, a national market that rates as statistically unconcentrated, and a long tail of small independents beneath a handful of very large operators.

The distinctive thing about 4413 is that its two children are not the same business, and the contrast between them is the whole point of reading at this level. One child (auto parts) is roughly twice the size of the other and is unusually investable in the public market; the other (tire dealers) is smaller, more service-driven, and mostly private — the best businesses in it are owned by families, private equity, or tiremakers, not by public shareholders. Sections 2 and 4 draw out that split; the rest of this page treats the group as a whole and points you to the two child primers (44133 and 44134) for the depth.

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2. What's inside — the two child industries and how they differ

NAICS is a nested hierarchy: each four-digit industry group breaks into one or more five-digit industries. Code 4413 breaks into exactly two, and they are genuinely different animals:

Two takeaways from the table. First, size and ownership move together in opposite directions: the bigger child (parts) is the one you can actually buy in size on a stock exchange, while the smaller child (tires) is where the best assets stay private. Second, the economics differ at the core — parts retailing is a product-margin, distribution-density business, whereas tire retailing is a service-attachment business where the tire itself barely makes money. An investor who treats "auto aftermarket retail" as one undifferentiated thing will misjudge both.

Scope — what the group excludes. Both children are "primary business" categories, so 4413 counts stores whose main business is parts or tires. It deliberately excludes, and sends those dollars elsewhere: repair-and-installation labor (NAICS 811, general auto repair); new/used-car dealers' service departments (441110/441120); wholesale parts and tire distribution (423120/423130); warehouse clubs and supercenters like Costco and Walmart (455211); tire manufacturers and retreaders (326211/326212); and the large volume of parts and tires sold online or through mass merchants (much of it 454110) [1]. The federal figures below therefore mean "money spent at dedicated parts stores and tire dealers," not "all money spent keeping American cars running" — a gap Section 3 quantifies.

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3. How big it is (this level's rollup figures)

These are our ground-truth federal statistics for NAICS 4413. Receipts, firm counts, and concentration come from the U.S. Census Bureau's 2022 Economic Census; establishment, employment, and payroll counts come from the 2023 County Business Patterns (CBP), a separate annual Census survey [2][3].

The children add up. These group figures are the two children summed: parts + tires give $95.35B + $43.3B ≈ $138.69B in receipts, 38,567 + 20,250 ≈ 58,817 establishments, and 380,068 + 170,169 ≈ 550,237 employees — exact matches on the CBP counts, confirming the rollup is clean [4][5]. (Firms are the one line that doesn't sum tidily: 17,199 + 11,132 = 28,331 versus 28,285 reported, because a company operating in both children can be counted once in each child but only once in the group.)

A useful average, and why it misleads. Receipts divided by firms is about $4.9 million per firm, and about $2.36 million per establishment with ~9 employees each — the profile of a modest neighborhood store [2][3]. But that average is badly skewed: a few national chains take a large share while thousands of small operators split the rest, so the typical independent is far smaller than the mean.

Concentration — and why the group looks more fragmented than it is. The Herfindahl-Hirschman Index (HHI, a standard 0-to-10,000 concentration gauge that sums the squared market shares of all firms) is just 353.9 for the group — well below the 1,000 mark and far below the 1,800 "highly concentrated" line in the 2023 federal Merger Guidelines, so the national market rates as unconcentrated [2][16]. Notice that the group's HHI (354) is lower than either child's (parts 645, tires 480), and its CR4 (34.2%) is lower than either child's CR4 (parts 46.9%, tires 37.0%) [4][5]. That is an artifact of blending two partly separate markets: a parts-counter chain and a tire shop don't really compete for the same sale, so pooling them dilutes the measured concentration and understates how much pricing power the leaders hold in their own lanes. In fact the group's top four are essentially the parts giants — parts' CR4 of 46.9% is ~$44.7B, which is ~32% of the whole group, almost the entire 34.2% group CR4 — confirming that the auto-parts chains dominate the combined level. Real antitrust markets here are usually local or channel-specific, where concentration runs much higher than any national number [16].

Undercount caveat — two layers, and it matters most here. First, the Census surveys cover businesses with paid employees, so they undercount nonemployer firms, sole proprietors, and the very smallest independents — and small, individual ownership is common across both children's long tails, so the true operator count is higher than 28,285 [3]. Treat these as an employer-based floor. Second and larger, the $138.69 billion is only the specialty-store channel. It omits tires and parts sold by clubs, supercenters, repair shops, and car dealers, all the online/mass-merchant volume, wholesale, and repair labor. Industry researchers put the whole U.S. light-vehicle aftermarket north of $400 billion, and the total U.S. tire market alone near $56 billion in 2025 — both well above the slices this code captures [14][15]. The gap is scope, not error.

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4. Investable universe (where value concentrates across the children)

The group's investability is lopsided toward the parts child, and understanding that asymmetry is the main reason to read at this level.

The auto-parts child (44133) is where the public value sits. For a retail industry it is unusually concentrated in a few large, high-quality listed names:

• AutoZone (NYSE: AZO) and O'Reilly Automotive (NASDAQ: ORLY) — the two purest, most profitable operators, both effectively perpetual share-buyback compounders [8][9].
• Genuine Parts Company (NYSE: GPC) — the NAPA distributor, a dividend payer with a large industrial arm, planning to separate its automotive and industrial businesses into two public companies (targeted first quarter 2027) [10].
• Advance Auto Parts (NYSE: AAP) — a higher-risk operational turnaround [11].
• CarParts.com (NASDAQ: PRTS) — online-only, economically relevant but generally outside this store-based code [11].

The tire child (44134) is mostly private. Public exposure is thin and largely indirect [5]:

• The closest listed near-pure-play is Monro (NASDAQ: MNRO), where tires were roughly 48% of recent-year sales — currently a small-cap operational turnaround [5].
• Broader exposure comes through tiremakers that also run stores — Goodyear (NASDAQ: GT), Bridgestone (Tokyo: 5108 / OTC: BRDCY), and Michelin (Euronext Paris: ML) / Sumitomo (Tokyo: 8053) — for whom retail is only a slice of a global manufacturing business [5].
• The largest and best tire retailers are private or manufacturer-owned: Discount Tire (family/employee-owned, the largest U.S. independent), Mavis (private equity; largest by location count), Bridgestone's company stores, Les Schwab, Sun Auto, and Big Brand [5].

Across the whole group, then, value concentrates in two very different pools: a public pool dominated by four or five parts names, and a private pool — thousands of independent parts stores, private-equity tire and service platforms, single-tenant net-lease real estate under the chains, and manufacturer-owned store networks. There is no pure-play auto-parts-and-tire-retail exchange-traded fund (ETF); the listed names appear inside broad consumer-discretionary and specialty-retail funds. Full company tables and private-owner detail live in the two child primers.

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5. How the money works

The two children earn their keep differently, and the group economics are a weighted blend of the two:

• Parts retailing (the larger, ~69% slice) is a product-spread and availability business. Retailers earn the margin between selling price and product cost, net of store labor, rent, distribution, and returns. Gross margins run rich for retail (low-40s to low-50s percent). The competitive moat is having the right part now — built on expensive, multi-echelon hub-and-spoke distribution — not on shelf price, and the customer splits into higher-margin DIY (do-it-yourself) consumers and lower-margin but stickier DIFM (do-it-for-me) professional shops. Suppliers finance much of the inventory, and the best operators return excess cash through buybacks (AZO, ORLY) or a rising dividend (GPC) [4][8][9][10].
• Tire retailing (the smaller, ~31% slice) is a service-attachment business. The tire itself carries a respectable ~40% gross margin but is shoppable and price-transparent — its real job is to get a car onto a lift. The profit lives in the service and add-ons that follow (alignments, brakes, batteries, road-hazard warranties), which in integrated shops can be the majority of gross profit [5].

A metric both children live by is comparable-store sales ("comps," sales at stores open at least a year — O'Reilly has posted 33 straight positive years) [9]. And both attract financial buyers for the same reason: stores are typically leased (so growth is funded per-store), demand recurs, and roll-up math rewards scale — a small shop bought at a low single-digit multiple of earnings and folded into a large platform re-rates toward the platform's higher multiple. Full margin tables and the consolidation-multiple ladder are in the child primers.

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6. Demand drivers

The demand case is shared across both children and is the reason the group is defensive. It tracks the fleet, not new-car sales:

• A large, aging fleet. About 289 million light vehicles are on U.S. roads, and the average one reached a record 12.8 years old in 2025; older, out-of-warranty vehicles need more parts and more tire/service work, and their owners buy from these stores [6].
• Miles driven. Wear is a function of use — U.S. vehicle-miles traveled reached 3.29 trillion in 2024, back at pre-pandemic highs — and tires in particular wear strictly by the mile (a set lasts ~3–5 years / 40,000–60,000 miles) [7].
• Affordability keeps cars on the road. Stretched new- and used-car prices push owners to repair rather than replace, and the segment is counter-cyclical — DIY repair rises in downturns.
• Electric vehicles (EVs) — a split signal. EVs need less routine maintenance (a headwind for the parts and service mix over time) but are heavier and higher-torque, so they wear tires ~20% faster (a tailwind for the tire child's volume) [5][6]. Net effect: EVs reshape the product mix more than they shrink it (judgment).

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7. Regulation

Lightly regulated as retail goes; no federal license is needed to open a parts store or tire shop, which is part of why the independent long tail persists. The policy touchpoints are largely shared across both children:

• Right to Repair — the defining fight for the parts side: independent shops' access to vehicle diagnostic data and software, advanced by state laws and the federal REPAIR Act [15].
• Trade and tariffs — the dominant policy force for the tire side: stacked antidumping and countervailing duties on imported passenger and light-truck tires, plus 2025 auto-parts tariff actions, raise landed costs that get passed through as price increases — a live margin wildcard for both children [16].
• Vehicle safety — Federal Motor Vehicle Safety Standards from the National Highway Traffic Safety Administration (NHTSA), including tire performance and pressure-monitoring rules and dealer recordkeeping for recalls [5].
• Environmental and workplace rules — Environmental Protection Agency (EPA) standards on used oil, batteries, and refrigerants; mostly state-level scrap-tire fees and disposal rules; and Occupational Safety and Health Administration (OSHA) rim/wheel-servicing rules for tire shops [5]. Warranty-choice protection under the Magnuson-Moss Warranty Act rounds out the set. Diligence on environmental and scrap-tire obligations should be done state by state.

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8. Consolidation

Consolidation is the defining dynamic of the whole group, but it runs on different engines in the two children:

• Parts (44133): organic expansion plus disciplined roll-ups by the incumbents. Genuine Parts reported 50-plus acquisitions adding 250-plus locations in 2025 (mostly independent NAPA stores), O'Reilly opened 207 net new stores, and Advance is pruning weak stores in a restructuring; private equity trades secondary distributors (Worldpac sold to Carlyle, ~$1.5B, 2024) [4][11].
• Tires (44134): a faster, private-equity-led roll-up. Mavis has grown past 3,500 locations through deals including Midas and an announced ~$700M acquisition of Pep Boys; other sponsor-backed platforms (Sun Auto, Big Brand, Les Schwab) keep buying, and distribution has been turbulent — American Tire Distributors went through Chapter 11 and an asset sale in 2024–2025 [5].

The common thread is that a small shop bought cheaply and folded into a large, well-run platform mechanically re-rates upward, which is why capital keeps flowing into both lanes. The strongest thesis in each is regional density; the failure mode in each is overpaying or keeping weak stores (Advance is the parts cautionary tale; over-levered platforms are the tire one). Full deal histories are in the child primers.

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9. Risks

The risk set is shared, weighted by which child dominates each risk:

• The EV mix shift (long-term). Fewer wear parts per vehicle pressures the parts child; the loss of high-margin service work (no oil changes; regenerative braking means less brake work) threatens the tire child's service model — even as EV tire volume rises [5][6].
• E-commerce price competition. Amazon, Walmart, and RockAuto erode product margins on both parts and tires, concentrating profit in service and availability.
• Tariff and input-cost shocks. Import duties and supply-chain disruption squeeze margins across both children [16].
• Inventory and obsolescence on the parts side; technician labor shortages capping throughput on the service side.
• Execution risk. Advance Auto Parts is the parts turnaround cautionary tale; sloppy integration is the roll-up one.
• Roll-up leverage and interest-rate sensitivity. Many private-equity tire platforms and the buyback-heavy parts chains alike carry debt that magnifies a downturn.
• Valuation. A great business can still be a poor investment at an excessive multiple — most relevant to the premium public parts names.

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10. How to invest, and the outlook

The clean way to think about it: the two children are two different investing games.

• For public-market investors, the parts child is the main event. AZO and ORLY for buyback-driven compounding, GPC for dividend income plus a possible 2027 automotive spin-off, AAP as a turnaround, PRTS for pure online exposure [8][9][10][11]. The tire child offers little direct public exposure — MNRO as a small-cap near-pure-play, or GT and the foreign-listed tiremakers as manufacturing-led plays with retail attached [5]. There is no pure-play ETF for either child; the names sit inside broad consumer-discretionary and retail funds.
• For private investors, the tire child is the deeper pond. Own a shop or small group and build local density, franchise into an established banner, back a private-equity platform (generally accredited/institutional-only), or hold the net-lease real estate these shops occupy [5]. The parts side offers parallel private routes — a franchised or independent NAPA/Carquest store, regional roll-ups and distributors, inventory-and-receivables lending — but a larger share of its value is already listed [4].

Outlook (forward-looking judgment, not a guarantee). The base case for the group is durable replacement demand with a changing mix: a record-old, still-growing fleet and stretched car affordability keep vehicles in the repair sweet spot, favoring scaled operators with the best availability, delivery, service throughput, and data systems. The near-term swing factor is tariffs (a direct margin variable for both children); the long-term one is the EV transition, which reshapes rather than erases per-vehicle demand — pressuring parts and service volumes while lifting tire wear. Consolidation is very likely to continue in both lanes. The most important single point at this level: do not treat 4413 as one business. The parts child and the tire child differ in size, ownership, economics, and access — and the group's low headline concentration understates how much pricing power the leaders hold in their own lanes. For the full analysis, company tables, and diligence detail, read the two child primers — 44133 (Auto Parts & Accessories Retailers) and 44134 (Tire Dealers).

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Sources

Our ground-truth figures for this level are the Economic Census 2022 concentration/receipts tables and the 2023 County Business Patterns [2][3]; the remaining citations are carried up from the two child primers (44133/441330 and 44134/441340), whose own Sources lists hold the complete references.

1. U.S. Census Bureau, "2022 NAICS — 4413 Automotive Parts, Accessories, and Tire Retailers; 441330 and 441340 definitions and exclusions (incl. 811, 441110/441120, 423120/423130, 455211, 326211/326212, 454110)," 2022. https://www.census.gov/naics/?input=4413&year=2022
2. U.S. Census Bureau, "Economic Census 2022 — receipts, firms, and concentration (NAICS 4413): CR4/CR8/CR20/CR50, HHI," 2022/2025 (this level's ground-truth stats). https://data.census.gov/table/ECNSIZE2022.EC2200SIZECONCEN?q=4413
3. U.S. Census Bureau, "County Business Patterns (CBP), 2023 — establishments, employment, annual and Q1 payroll (NAICS 4413)," 2023. https://www.census.gov/programs-surveys/cbp.html
4. Histometrics child primer — NAICS 44133 / 441330 (Automotive Parts and Accessories Retailers), carrying the full sourced detail on AutoZone, O'Reilly, Genuine Parts, Advance Auto Parts, CarParts.com, and the underlying federal, demand, regulatory, and consolidation sources synthesized here.
5. Histometrics child primer — NAICS 44134 / 441340 (Tire Dealers), carrying the full sourced detail on Monro, Goodyear, Bridgestone, Michelin/Sumitomo, Discount Tire, Mavis, and the underlying federal, trade, safety, and environmental sources synthesized here.
6. S&P Global Mobility, "U.S. Vehicle Age Rises Again to 12.8 Years in 2025 — 289M light vehicles in operation," May 21, 2025. https://press.spglobal.com/2025-05-21-U-S-Vehicle-Age-Rises-Again-to-12-8-Years-in-2025-According-to-S-P-Global-Mobility
7. Federal Highway Administration, "Highway Statistics 2024 — Annual Vehicle Distance Traveled (3.29T total)," 2026. https://www.fhwa.dot.gov/policyinformation/statistics/2024/vm1.cfm
8. AutoZone, Inc., "Form 10-K, fiscal 2025 (ending Aug 30, 2025)," 2025. https://www.sec.gov/Archives/edgar/data/866787/000110465925102611/azo-20250830x10k.htm
9. O'Reilly Automotive, Inc., "Form 10-K, fiscal 2025," 2026. https://www.sec.gov/Archives/edgar/data/898173/000089817326000009/orly-20251231x10k.htm
10. Genuine Parts Company, "Form 10-K, fiscal 2025; plan to separate automotive and industrial businesses into two public companies (targeted Q1 2027)," 2026. https://www.genpt.com/2026-02-17-Genuine-Parts-Company-Announces-Plan-to-Separate-Automotive-and-Industrial-Businesses-Into-Two-Industry-Leading-Public-Companies
11. Advance Auto Parts, Inc., "Form 10-K, fiscal 2025; Worldpac sold to Carlyle (~$1.5B, 2024)," 2026; and CarParts.com, Inc., "Form 10-K, fiscal 2025." https://www.sec.gov/Archives/edgar/data/1158449/000119312526051305/aap-20260103.htm
12. Auto Care Association, "Right to Repair and the REPAIR Act — fact sheet," 2025; and Congressional Research Service, "Access to Motor Vehicle Software and Data (R48131)," 2024. https://www.autocare.org/government-relations/current-issues/right-to-repair
13. U.S. International Trade Commission / U.S. Trade Representative, "Antidumping and countervailing duties on passenger and light-truck tires; 2025 auto-parts tariff actions," 2024–2025 (as summarized in the 44134 child primer).
14. MEMA / Auto Care Association, "U.S. automotive aftermarket size (~$400B+ light-vehicle aftermarket)," 2024–2025. https://www.mema.org/
15. Mordor Intelligence, "United States Tire Market Size, Share & 2030 Trends Report (~$56B, 2025)," 2025. https://www.mordorintelligence.com/industry-reports/united-states-tire-market
16. U.S. Department of Justice & Federal Trade Commission, "2023 Merger Guidelines — Guideline 1 (HHI thresholds; relevant-market definition)," 2023. https://www.justice.gov/atr/merger-guidelines