B737 flight crew reported misunderstanding an ATC clearance on arrival into smf.

Attributes
ACN	1347794
Time
Date	201604
Local Time Of Day	1201-1800
Place
Locale Reference	ZOA.ARTCC
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	STAR SUUTR2
Flight Plan	IFR
Person 1
Function	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 169
Person 2
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 129
Events
Anomaly	ATC Issue All Types Deviation - Altitude Crossing Restriction Not Met Deviation - Altitude Overshoot Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy

Narrative:

Cruising at FL400 to smf we were issued a clearance to descend to FL360 then cleared to descend via the suutr 2 RNAV arrival into smf. Approaching FL360 we were told to continue to FL280 and given a frequency change. Descending through FL360 I reported our altitude descending to FL280 and cleared to descend via the suutr 2 as we had understood the previous controller. Immediately ATC clarified to maintain 280 which we did; until receiving clearance shortly after leveling to descend via the suutr 2. Noting that we were cleared to maintain 280; I told the first officer (first officer) that trloc at or above 290 was not a player. He concurred and deleted the restriction from the FMC. On descent into smf; norcal proceeded to ask us to call regarding a possible pilot deviation.only thing I can suggest is if ATC issues a clearance that seems to be missing something; ask. In hindsight it seemed odd that we would be given a new descend to altitude without being told to maintain or continue descend via. On check-in this was clarified immediately by ATC and I honestly don't know what else could have been done. There was no altitude deviation; separation problems or anything else. Merely communicating what we had understood our clearance to be and being corrected by ATC was (I think) an appropriate action. Obviously; in this increasingly complicated environment we work in clarification at the earliest point of question would be in order. If a clearance seems to be open ended or missing an element; inquire.

Original NASA ASRS Text

Title: B737 flight crew reported misunderstanding an ATC clearance on arrival into SMF.

Narrative: Cruising at FL400 to SMF we were issued a clearance to descend to FL360 then cleared to descend via the SUUTR 2 RNAV Arrival into SMF. Approaching FL360 we were told to continue to FL280 and given a frequency change. Descending through FL360 I reported our altitude descending to FL280 and cleared to descend via the SUUTR 2 as we had understood the previous Controller. Immediately ATC clarified to maintain 280 which we did; until receiving clearance shortly after leveling to descend via the SUUTR 2. Noting that we were cleared to maintain 280; I told the FO (First Officer) that TRLOC at or above 290 was not a player. He concurred and deleted the restriction from the FMC. On descent into SMF; NorCal proceeded to ask us to call regarding a possible Pilot Deviation.Only thing I can suggest is if ATC issues a clearance that seems to be missing something; ask. In hindsight it seemed odd that we would be given a new descend to altitude without being told to maintain or continue descend via. On check-in this was clarified immediately by ATC and I honestly don't know what else could have been done. There was no altitude deviation; separation problems or anything else. Merely communicating what we had understood our clearance to be and being corrected by ATC was (I think) an appropriate action. Obviously; in this increasingly complicated environment we work in clarification at the earliest point of question would be in order. If a clearance seems to be open ended or missing an element; inquire.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.