The Miami Marlins have the highest ERA by a team in a game, with an ERA of 30.38 against the Braves on September 9, 2020.

Interpreted as:

highest era in a regular-season game by a team

	TEAM	ERA	DATE	TM		OPP	RESULT	SO	SHO	SV	IP	H	ER	R	HR	BB	HBP	IBB	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	H/9
1	Marlins	30.38	9/9/2020	MIA	@	ATL	L 9-29	9	0	0	8.0	23	27	29	7	9	1	0	58	0	10.13	10.13	1.00	7.88	15.5	15.5	4.00	.500	32.63	25.88
2	Orioles	30.00	8/22/2007	BAL	vs	TEX	L 3-30	11	0	0	9.0	29	30	30	6	8	0	0	65	1	11.00	8.00	1.38	6.00	16.9	12.3	4.11	.575	30.00	29.00
3	Orioles	29.25	4/19/1996	BAL	@	TEX	L 7-26	2	0	0	8.0	19	26	26	5	13	1	0	55	1	2.25	14.62	0.15	5.63	3.6	23.6	4.00	.412	29.25	21.38
4	Browns	29.25	6/8/1950	SLA	@	BSA	L 4-29	2	0	0	8.0	28	26	29	7	11	0	0	64	0	2.25	12.38	0.18	7.88	3.1	17.2	4.88	.477	32.63	31.50
5	Red Sox	29.08	5/4/1963	BOS	@	KCA	L 3-14	3	0	0	4.1	12	14	14	0	7	0	1	32	1	6.23	14.54	0.43	0.00	9.4	21.9	4.38	.545	29.08	24.92
6	Mets	28.13	7/31/2018	NYM	@	WSH	L 4-25	6	0	0	8.0	26	25	25	5	8	1	1	59	0	6.75	9.00	0.75	5.63	10.2	13.6	4.25	.538	28.13	29.25
7	Marlins	28.13	6/27/2003	FLA	@	BOS	L 8-25	7	0	0	8.0	28	25	25	3	7	1	0	57	0	7.88	7.88	1.00	3.38	12.3	12.3	4.38	.641	28.13	31.50
8	Red Sox	27.00	7/22/2022	BOS	vs	TOR	L 5-28	9	0	0	9.0	29	27	28	5	5	1	0	63	2	9.00	5.00	1.80	5.00	14.3	7.9	3.78	.558	28.00	29.00
9	Mets	27.00	6/11/1985	NYM	@	PHI	L 7-26	3	0	0	8.0	27	24	26	2	7	1	1	59	1	3.38	7.88	0.43	2.25	5.1	11.9	4.25	.543	29.25	30.38
10	Orioles	27.00	6/26/1978	BAL	@	TOR	L 10-24	6	0	0	8.0	24	24	24	2	8	0	0	56	1	6.75	9.00	0.75	2.25	10.7	14.3	4.00	.550	27.00	27.00
11	Athletics	27.00	4/23/1955	KCA	vs	CWS	L 6-29	4	0	0	9.0	29	27	29	7	6	1	1	63	1	4.00	6.00	0.67	7.00	6.3	9.5	3.89	.489	29.00	29.00
12	Reds	27.00	7/4/1951	CIN	@	PIT	L 4-16	1	0	0	5.0	17	15	16	3	4	0	0	39	0	1.80	7.20	0.25	5.40	2.6	10.3	4.20	.452	28.80	30.60
13	Rockies	26.00	8/18/1995	COL	vs	CHC	L 7-26	8	0	0	9.0	27	26	26	3	6	0	0	60	0	8.00	6.00	1.33	3.00	13.3	10.0	3.67	.558	26.00	27.00
14	Rangers	25.88	9/30/2000	TEX	@	OAK	L 2-23	10	0	0	8.0	24	23	23	4	10	0	0	58	1	11.25	11.25	1.00	4.50	17.2	17.2	4.25	.588	25.88	27.00
15	Rockies	25.00	6/24/2023	COL	vs	LAA	L 1-25	3	0	0	9.0	28	25	25	5	6	1	0	59	2	3.00	6.00	0.50	5.00	5.1	10.2	3.78	.523	25.00	28.00
16	Mets	24.75	4/30/2017	NYM	@	WSH	L 5-23	6	0	0	8.0	23	22	23	7	6	0	3	54	3	6.75	6.75	1.00	7.88	11.1	11.1	3.63	.457	25.88	25.88
17	Athletics	24.75	8/25/2011	OAK	@	NYY	L 9-22	9	0	0	8.0	21	22	22	5	13	1	1	58	1	10.13	14.62	0.69	5.63	15.5	22.4	4.25	.533	24.75	23.63
18	Indians	24.75	6/4/2002	CLE	@	MIN	L 2-23	4	0	0	8.0	25	22	23	3	7	0	1	57	2	4.50	7.88	0.57	3.38	7.0	12.3	4.00	.512	25.88	28.13
19	Marlins	24.75	8/31/1996	FLA	@	CIN	L 8-22	9	0	0	8.0	18	22	22	5	11	0	2	52	0	10.13	12.38	0.82	5.63	17.3	21.2	3.63	.481	24.75	20.25
20	Astros	24.75	6/3/1987	HOU	@	CHC	L 7-22	6	0	0	8.0	21	22	22	6	9	0	0	54	1	6.75	10.13	0.67	6.75	11.1	16.7	3.75	.455	24.75	23.63
21	Tigers	24.75	6/18/1953	DET	@	BOS	L 3-23	6	0	0	8.0	27	22	23	1	9	0	1	60	1	6.75	10.13	0.67	1.13	10.0	15.0	4.50	.591	25.88	30.38
22	Orioles	24.00	4/20/2025	BAL	vs	CIN	L 2-24	6	0	0	9.0	25	24	24	3	11	2	0	64	0	6.00	11.00	0.55	3.00	9.4	17.2	4.00	.524	24.00	25.00
23	Tigers	24.00	9/9/2004	DET	vs	KCR	L 5-26	6	0	0	9.0	26	24	26	1	8	0	0	62	1	6.00	8.00	0.75	1.00	9.7	12.9	3.78	.532	26.00	26.00
24	Reds	23.63	7/6/2009	CIN	@	PHI	L 1-22	9	0	0	8.0	21	21	22	4	7	1	0	52	0	10.13	7.88	1.29	4.50	17.3	13.5	3.50	.548	24.75	23.63
25	Devil Rays	23.63	7/22/2007	TBD	@	NYY	L 4-21	8	0	0	8.0	25	21	21	6	7	1	0	56	1	9.00	7.88	1.14	6.75	14.3	12.5	4.00	.559	23.63	28.13